Mesh creating device, mesh creating method and mesh creating program

ABSTRACT

Herein disclosed is a mesh creating device, a mesh creating method and a mesh creating program which speed up the analysis processing without deteriorating analysis accuracy and to effectively facilitate handling of the data after creation of the analysis model. The mesh creating device creates an analysis mesh for the data of a construction composed of a plurality of objects by creating one or more groups of attributes to which said plurality of objects belong respectively, setting mesh creating specifications on an object attribute-by-attribute basis according to the one or more groups of attributes, and conducting mesh creations according to the set object attribute mesh creating specifications.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/641,006 filed Aug. 15, 2003, now pending, and this application claimsthe priority of Japanese Patent Application No. 2002-254041, filed onAug. 30, 2002, in the Japanese Patent Office, the disclosures of whichare incorporated herein in their entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mesh creating device, a mesh creatingmethod and a mesh creating program which are suitable for use inexecution of a heat and/or fluid analysis simulation using a calculatingmodel for a device composed of a plurality of kinds of parts.

2. Description of the Related Art

Recently, it is often performed in a computer to simulate a physicalmovement of a device model that is designed by employing CAD(computer-aided design) in order to verify the model. For example, ananalysis such as a thermal conduction analysis, a fluid analysis, astructural analysis, an electromagnetic field analysis, andelectromagnetic analysis and the like is generally performed byemploying the finite volume method and/or finite element method in whicha mesh is formed in a analyzing field, as a result of which a pluralityof objects divided by such a mesh are analyzed. In this case, it isperformed to remove parts which are each regarded as unimportance inview of the analysis in order to converge the analysis result and toreduce an analysis period of time.

In Japanese Patent Laid-Open Publication No. 2002-183223 for example,there is disclosed a mesh creation for a construction such as electricalappliance wherein a plurality of objects corresponding respectively to aplurality of parts constituting the electrical appliance are handled asan analysis object. According to this publication, a heat flux iscalculated as importance in the respective analysis simulations of theplurality of objects by using information regarding a plurality of kindsof attributes (attribute information) inclusive of coordinateinformation of the plurality of objects so that parts which have beendecided to be of low importance based on the calculated heat flux valuesare removed and then a mesh for an analysis is created for theconstruction except the removed objects.

This conventional mesh creation for the construction composed of theplurality of parts is performed by using a division specificationdefined constantly regardless of attributes of the respective parts. Forthis reason, when the respective analysis simulations of the pluralityof parts are performed, parts which are regarded as importance in theanalysis (each part should essentially be finely analyzed) and partswhich are not regarded as importance (each part is not need to be finelyanalyzed) are divided on the same level so that it is difficult to catchbalance between improvement in analysis accuracy and speeding-up ofanalysis processing. Specifically, in order to improve the analysisaccuracy, parts which are not regarded as importance will be finelyanalyzed so that futile analysis processing operations are increased toobstruct the speeding-up of analysis. Furthermore, when a mesh iscreated for a construction composed of a plurality of parts, apredetermined processing thereof is performed regardless of attributesof the respective parts. After the mesh creation, all of the parts arehandled as the same class without discrimination of the physicalproperties thereof. Therefore, it often happens that inconveniences arecaused in handling an analysis model after mesh creation processing. Forexample, it is inconveniently impossible to reproduce an assembly statecaptured before creation of its analysis model.

Accordingly, an object of the present invention is to provide a meshcreating device, a mesh creating method and a mesh creating programwhich are adapted to speed up an analysis processing withoutdeteriorating analysis accuracy. Also, another object of the presentinvention is to provide a mesh creating device, a mesh creating methodand a mesh creating program which are adapted to facilitate an handlingof data after an analysis model of an object to be analyzed.

SUMMARY OF THE INVENTION

In order to address the above-mentioned problem and the other, thepresent invention has been accomplished. According to an aspect of thepresent invention, there is provided a mesh creating device adapted tocreate a mesh for use in analysis for data of an construction composedof a plurality of objects. The mesh creating device capable of creatingan analysis mesh for the data of a construction composed of a pluralityof objects, comprising:

a first mesh creating specification setting section adapted to setattributes to which the plurality of objects belong respectively and setmesh creating specifications for the respective attributes; and

a mesh creating section adapted to conduct mesh creations according tothe set mesh creating specifications.

With this configuration, it is possible to create a mesh according tothe mesh specification which is adapted for an attribute of the object,thereby speeding up the analysis processing without deteriorating theanalysis accuracy.

Here, parts of the construction are exemplified as objects in thefollowing embodiments and the objects include an analysis object such asan air space formed within the construction.

Further, it is possible to include in the attributes attribute categoryinformation which designates categories of the attributes and attributediscriminative information which designates discriminations among theattributes. For example, the attribute category information may includeat least one of class, material, heating element and object name(article name). On the other hand, the attribute discriminativeinformation may include information representative of one material of aplurality of materials, information representative of one class of aplurality of classes and information representative of a kind of one ofheating elements.

In the mesh creating device, the mesh creating specification includesthe number of division for each object belonging to one attribute of aplurality of attributes. With this configuration, it is possible tofinely or coarsely divide an object depending on its attribute. As aresult, a portion which is important in analysis of the object candensely be calculated but a portion which is not important in analysisof the object can roughly be calculated, thereby efficiently speeding-upthe analysis processing without deteriorating analysis accuracy.

Also, in the mesh creating device, the mesh creating specificationincludes removal enable/disable information for the object belonging tothe attribute.

Also, the mesh creating device further comprises a priority ordersetting section adapted to set a priority order of a mesh creatingspecification every group divided on attribute-by-attribute basis basedon the set mesh creating specifications, as a result of which the meshcreating section can conduct mesh creations based on the set meshcreating specifications according to the set priority order thereof.With this configuration, it is possible to conduct the mesh creationsaccording to the set priority orders thereof (or to conduct a meshcreation based on a mesh creating specification having the highestpriority order) in the event that an object (part) belongs to aplurality of attributes and that different mesh creating specificationsare set for those attributes.

Also in this case, the priority order setting section can set thepriority orders based on the mesh creating specifications. For example,the priority order of a mesh creating specification set for an attributeby which the number of division should be set larger can be set higherthan that of a mesh creating specification for an attribute by which thenumber of division should be set smaller. With this configuration, thedivision of an object will be conducted with the largest number ofdivision among those set for a plurality of attributes to which theobject belongs, thereby conveniently maintaining the number of divisionfor an object which is very important in analysis and then leading to ahigh reliability.

Furthermore, the mesh creating device further comprises a second meshcreating specification setting section which is adapted to set a meshcreating specification for the plurality of objects in total regardlessof the attributes to which the plurality of objects belong. With thisconfiguration, a mesh creation for all of parts (objects) constitutingthe construction can be conducted without defining some attributes towhich all of parts belong.

According to another aspect of the present invention, there is provideda mesh creating method of creating a mesh for use in analysis for thedata of a construction composed of a plurality of objects, comprisingthe steps of:

(a) setting attributes to which the plurality of objects belongrespectively and setting mesh creating specifications for the respectiveattributes; and

(b) conducting mesh creations according to the set mesh creatingspecifications.

Also, the mesh creating method further comprises (c) setting a priorityorder of a mesh creating specification every group divided onattribute-by-attribute basis based on the mesh creating specificationsset in the previous step (a), wherein, in the previous step (b), themesh creations are conducted according to the priority orders set in theprevious step (c).

According to yet another aspect of the present invention, there isprovided a mesh creating program for causing a computer to execute amesh creation processing to create a mesh for use in analysis,comprising the steps of:

(a) setting attributes to which a plurality of objects belongrespectively and setting mesh creating specifications for the respectiveattributes; and

(b) conducting mesh creations according to the set mesh creatingspecifications.

This mesh creating program can be stored in a computer readable storagemedium which comprises a portable storage medium such as a CD-ROM, aflexible disk (FD), a DVD disk, an opto-magnetic disk, an IC card andthe like, or a database storing computer programs.

Also, in the mesh creating program, the attribute includes attributecategory information which designates category of the attribute andattribute discriminative information which designates discriminationswithin the attribute. The attribute category includes at least one ofclass, material, heating element and object name. The mesh creatingspecification includes the number of division for an object belonging toan attribute.

Also, in the mesh creating program, the mesh creating specificationfurther includes removal enable/disable information of the objectbelonging to the attribute. Moreover, the mesh creating program ischaracterized by further comprising (c) setting the priority order ofthe mesh creating specification every group divided onattribute-by-attribute basis, wherein, in the previous step (b), themesh creations are conducted based on the mesh creating specificationsaccording to the priority orders set in the previous step (c). Inparticular, the priority order is set based on the mesh creatingspecification in the previous step (c). Also in the previous step (c),the priority order is set higher as the number of division becomeslarger. Furthermore, the mesh creating program is characterized byfurther comprising a second step of setting a mesh creatingspecification for the plurality of objects in total regardless of theattributes to which the plurality of objects belong.

These and other aspects of the present invention will be apparent fromthe following specific description, given by way of example, withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram showing a mesh creating deviceaccording to a preferred embodiment of the present invention;

FIG. 2 is a schematic view showing a setting screen (total designationscreen) prepared for a mesh creating specification;

FIG. 3 is a schematic view showing a setting screen prepared for classesas attribute information;

FIG. 4 is a schematic view showing a setting screen prepared formaterials as attribute information;

FIG. 5 is a schematic view showing a setting screen prepared for thenecessity and nonnecessity of heating as attribute information;

FIG. 6 is a schematic view showing a setting screen prepared for user'soptions as attribute information;

FIG. 7 is a schematic view showing a setting screen for priority order;

FIG. 8 is a flow chart showing an entire operation of the preferredembodiment of the present invention; and

FIG. 9 is an example of output mode according to the preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram showing a mesh creating deviceaccording to a preferred embodiment of the present invention. The meshcreating device 1 comprises: an input section 2 for inputting part (asan object and which may include an air space) information from productinformation device; inputted part information storing section 3 forstoring therein the inputted part information outputted from the inputsection 2; a group forming section 4 for setting a group of parts everyattribute based on the inputted part information and setting a divisionspecification every group (or every attribute); a priority orderdeciding section 5 for deciding a priority order of a divisionspecification for a part included in each of the groups every group; amesh creating information producing/storing section 6 for producing andstoring information suitable for creating a mesh so as to perform aremoval or division of the part according to the mesh creatingspecification and based on the groups and the priority orders; a meshcreating section 7 for removing a part to be removed according to thismesh creating information and for creating a mesh suitable forperforming the division of a part; a mesh data storing section 8 forstoring therein mesh data created by the mesh creating section 7; outputdata producing section 9 for producing output data suitable foroutputting the mesh data thus created above; and an output section 10for outputting the output data. The output data outputted from theoutput section 10 is sent as analysis model data to an analysissimulating device and a display device.

The part information from the input section 2 includes attributeinformation such as a parts name, a parts class, a physical propertyvalue (material), an existence of heating (a part being a heatingelement or non-heating element) and a user option, as well as a parts IDand its shape data. In addition to the class and the physical propertiesas attribute categories, the attribute information may includediscriminative information in each attribute category (e.g., materials Aand B). The group forming section 4 is adapted to group inputted partsevery attribute. At that time, a part may belong to a plurality ofattributes. For each of parts which are grouped, a mesh creatingspecification is provided with a setting input for the possibility as towhether such a part should be removed every group or with a settinginput for the number of division. The setting input of this meshcreating specification may initially be given as part information or maybe inputted directly from the group forming section 4. In the event thata plurality of mesh creating specifications are set for a part belongingto a plurality of groups, the priority order deciding section 5 decidespriority order about which one of the mesh creating specifications setfor the part should priorly be handled.

In the above configuration, the input section 2, the inputted partinformation storing section 3, the group forming section 4, the priorityorder deciding section 5 and the mesh creating informationproducing/storing section 6 constitute a mesh creating specificationsetting section 11 according to the present invention.

The following description is provided to explain an operation of amethod for setting a mesh creating specification with reference to FIGS.2 to 6. In association with a plurality of parts (analysis construction)in total, FIG. 2 is a schematic view showing a setting screen (totaldesignation screen) prepared for the mesh creating specification andadapted to designate and set the number of division and the removal ofparts. In the total designation screen, the necessity or nonnecessity ofdivision and the number of division in the case of the necessity thereofare inputted and set in a division setting section 21. In an example asshown in FIG. 2, the necessity of division is checked by a check mark ina division designation box 21 a and the number of division (50) isdesignated in a divisional number designation box 21 b. Further, thereis provided in the total designation screen a removal setting section 24for unwanted parts. In this example, the necessity of a part as anobject to be removed is designated by a check mark and a size of itsremoved object is inputted and designated in a size designation box 25.In this example, it would be appreciated that a part having a size lessthan 10 mm in x, y, z directions is shown as an object to be removed.Furthermore, a group of mesh creating specifications set in this totaldesignation screen is indicated in a group number indication box 26 as agroup number “1”.

In association with parts belonging to the attribute of classes, FIG. 3is a schematic view showing a setting screen prepared for classes asattribute information and adapted to set a mesh creating specificationfor a group of parts every class and to set a group number thereof. In aclass setting screen as shown in FIG. 3, there are provided a class namedesignation box 30 by which class names (A, B, C, . . . ) are designatedand a division designation section 31 by which, every class name, thenecessity or nonnecessity of the division and the number of division inthe case of the necessity thereof are designated. In an example as shownin FIG. 3, the necessity of the division is checked by a check mark in adivision designation box 31 a and the number of division is designatedin a divisional number designation box 31 b.

Furthermore, a removal setting section 34 adapted to designate thepossibility of removal is provided in this setting screen. In the caseof removal, a removal enable box 34 a is checked by a check mark, but aremoval disable box 34 b is check by a check mark in the case ofnon-removal. Also, a group number indication box 36 is provided thereinin which a group number for a group of parts every class is indicated.In this example, the class name “B” is a removal object and thereforeits group number is not indicated in the group number indication box 36.Also, in this example, the class “A” is set in the number of divisionwith larger in numbers than those for the other classes and “disable”for its removal in the removal setting section 34 because the class “A”requires a more detailed calculation in thermal analysis. However, theclass “B” is a removal object because its existence has no influence onsuch a thermal analysis. Also, the class “C” is not so large ininfluence and therefore is set with small in numbers for the number ofdivision. With respect to the removal, parts of the class “C” followsconditions set in connection with the other attributes for the sameparts or conditions set in the total designation screen.

In association with parts belonging to the attribute of materials, FIG.4 is a schematic view showing a setting screen prepared for materials asattribute information and adapted to set a mesh creating specificationfor a group of parts every material and to set a group number thereof.In the setting screen prepared for materials as shown in FIG. 4, thereis provided a material name designation box 40 for setting materialnames (A, B, C, . . . ). In a division designation section 41, thenecessity or nonnecessity of the division and the number of division inthe case of the necessity thereof are set every material name. In anexample as shown in FIG. 4, the necessity of the division is checked bya check mark in a division designation box 41 a and the number ofdivision is designated in a divisional number designation box 41 b.Furthermore, a removal setting section 44 adapted to designate thepossibility of removal is provided in this setting screen. In the caseof removal, a removal enable box 44 a is checked by a check mark, but aremoval disable box 44 b is check by a check mark in the case ofnon-removal. Also, a group number indication box 46 is provided thereinin which a group name for a group of parts every class name isindicated. In this example, only the group name “C” is an object to bedivided. Also, in this example, there is no designation in the removalsetting section 44 and the possibility of removal of such parts isdecided in dependence on a higher one of priority orders set in thetotal designation screen and set for the other attributes.

In association with parts belonging to the attribute of heatingelements, FIG. 5 is a schematic view showing a setting screen preparedfor the necessity and nonnecessity of heating as attribute informationand adapted to set a mesh creating specification for a group of partsevery heating element and to set a group number thereof. In the settingscreen prepared for heating elements as shown in FIG. 5, there isprovided a heating element-name designation box 50 for setting heatingelement names (A, B). In a division designation section 51, thenecessity or nonnecessity of the division and the number of division inthe case of the necessity thereof are set every heating element nameindicated in the heating element-name designation box 50. In an exampleas shown in FIG. 5, the necessity of the division is checked by a checkmark in a division designation box 51 a and the number of division isdesignated in a divisional number designation box 51 b. Furthermore, aremoval setting section 54 for designating the possibility of removal isprovided in this setting screen. In the case of removal, a removalenable box 54 a is checked by a check mark, but a removal disable box 54b is check by a check mark in the case of non-removal. Also, a groupnumber indication box 56 is provided therein in which a group name for agroup of parts every class name is indicated. In this example, since theheating element is an important part in thermal analysis, the number ofdivision is set with large in numbers and the “disable” for removal isset. In particular, the heating element “B” is larger in influence onthe thermal analysis than that of the heating element “A”. Therefore,the heating element “B” is set in the number of division with larger innumbers than those for the heating element “A”.

In association with selection of a part name as the attribute of user'soptions, FIG. 6 is a schematic view showing a setting screen preparedfor user's options as attribute information and adapted to set a meshcreating specification for a group of parts every part name and to set agroup number thereof. In a part-name setting screen (an user's optionsetting screen) as shown in FIG. 6, there is provided a part-namedesignation box 60 for setting part names (A, B, C, . . . ). In adivision designation section 61, the necessity or nonnecessity of thedivision and the number of division in the case of the necessity thereofare set every part name designated in the part-name designation box 60.Furthermore, a removal setting section 64 for designating thepossibility of removal is provided in this setting screen. As well asthe part name (parts B, parts C, . . . ), the names of class, group andthe like involved in the respective attributes as described above(attribute categories) may be added to this setting screen as desired.Correspondingly, the division designation box and the divisional numberdesignation box can be increased in numbers in the division settingsection 61.

In the event that a part has a plurality of group numbers set everyattribute as described above, FIG. 7 is a schematic view showing asetting screen for deciding the priority order about which one of thegroup numbers should priorly be selected such that the meshspecification set for its selected group number is executed. In thisexample as shown in FIG. 7, the smaller the number of division, thelower priority order is set (the larger the number of division, thehigher priority order is set.). Also, the priority order for the meshcreating specification set the general setting screen is set at thelowest order. However, the priority order can optionally be set by theuser in a manner that, after selection of a group number as an object,its priority order can be varied by an operation button 71.

FIG. 8 is a flow chart showing an entire operation of the preferredembodiment of the present invention. First of all, shapes and attributesof parts are captured (S1) to create a prototype of a group everyattribute (class, material etc.) (S2). Then, a mesh creatingspecification (conditions of division and removal) for all ofcomponents, inclusive of parts, constituting a construction is set onthe total setting screen as shown in FIG. 2 (S3). By using the prototypecreated in the step of S2, a creation of group is executed everyattribute as shown in FIGS. 3 through 6 (setting of a mesh creatingspecification every attribute) (S4). Then, the priority orders for thecreated groups are decided or set as shown in FIG. 7, thereby endingsetting of the mesh creating specification.

Subsequently, a removal processing of parts to be removed or removalparts is executed before the creation of a mesh according to the meshcreating specification. In the step of S6, it is decided if there is anyremoval parts designated on the total setting screen. In the case thatthe removal parts are present (S6: True), a retrieval of the removalparts is executed and all of the retrieved parts are listed (S7). Then,it is decided whether the retrieved parts are designated as removaldisable parts under the other attributes. In the case that the retrievedparts are found to be removal enable parts (S8: True), the removalthereof is executed (S9). These processing steps (S8 and S9) areexecuted on all of the retrieved parts as listed above (S10). Afterexecution of such a general or total removal or in the case ofnon-necessity thereof (S6: False), the control flow proceeds to step S11wherein it is decided if there are any removal parts on anattribute-by-attribute basis as set in FIGS. 3 through 6 (S11). In thecase that the removal parts are present, a retrieval of the removalparts is executed and all of the retrieved parts are listed (S12). Ifthe retrieved parts are found to be removal enable parts (S13: True) asa similar manner to the step of S8 in connection with the otherattributes, the removal thereof is executed (S14) and the processingsteps (S13 and S14) are executed on all of the retrieved parts as listedabove (S15).

In this way, the removal of all of parts to be removed are completed.Thereafter the number of division based on the priority order isallocated to each of parts in step of S16. Then, all of parts are eachdivided according to the number of division (a mesh creation) (S17 andS18). After that divisional processing, an output type is selected (S19)and then the parts are grouped as desired (S20). The resultant data isduly transformed into an analysis format suitable for the analysissimulating device in consideration of the attribute information (such asmaterial or the like) (S21) and outputted (S22). FIG. 9 is an example ofoutput mode according to an output type. For example, the class isselected as output type and then a part number per class (attributediscrimination) is outputted and displayed. Thus, an assembly state ofthe construction can readily be reproduced from the data for theanalysis model, thereby providing a convenience to a user in handlingthereof.

According to the present invention, it is possible to speed up theanalysis processing without deteriorating analysis accuracy. Also, it ispossible to provide a mesh creating device, a mesh creating method and amesh creating program which are adapted to effectively facilitate anhandling of the data after creation of the analysis model.

While preferred exemplary embodiments of the present invention have beendescribed above, it is to be understood that further adaptations of theinvention described herein can be obtained by appropriate modificationsby one of ordinary skill in the art without departing from the scope ofthe present invention. Accordingly, although preferred configurations ofdevices, methods, and programs embodying the present invention have beendescribed, it should be understood that these devices, methods, andprograms may take on a wide variety of configurations and arrangementswithout departing from the scope of the present invention. Therefore,the scope of the present invention should be considered in terms of thefollowing claims and should not be limited to the details of thedevices, methods, and programs shown and described above.

1. A mesh creating device creating a mesh for use in analysis for dataof a construction composed of a plurality of objects, comprising: afirst mesh creating specification setting section creating one or moregroups of attributes to which said plurality of objects belongrespectively and setting mesh creating specifications on an objectattribute-by-attribute basis according to the one or more groups ofattributes; and a mesh creating section conducting mesh creationsaccording to the set object attribute mesh creating specifications.
 2. Amesh creating device as claimed in claim 1, wherein said attributes aregrouped according to a categorization of the attributes and an attributein each group of attributes is discriminated according to attributediscriminative information which designates discriminations within saidattribute.
 3. A mesh creating device as claimed in claim 2, wherein saidattribute category includes one or more of class, material, heatingelement or object name.
 4. A mesh creating device as claimed in claim 1,wherein said set mesh creating specifications for an attribute in agroup of attributes includes a number of division for each objectbelonging to the group of attributes.
 5. A mesh creating device asclaimed in claim 1, wherein said set mesh creating specifications for anattribute in a group of attributes includes removal enable/disableinformation for an object belonging to the group of attributes.
 6. Amesh creating device as claimed in claim 1, further comprising a secondmesh creating specification setting section setting a mesh creatingspecification for said plurality of objects in total regardless of saidgroups of attributes to which said plurality of objects belong.
 7. Amethod of creating a mesh for use in analysis for data of a constructioncomposed of a plurality of objects, comprising: creating one or moregroups of attributes to which said plurality of objects belongrespectively; setting mesh creating specifications on an objectattribute-by-attribute basis according to the one or more groups ofattributes; and conducting mesh creations according to the set objectattribute mesh creating specifications.
 8. A computer readable mediumstoring a mesh creating program causing a computer to execute a meshcreation process for analyzing data of a construction composed of aplurality of objects, by: creating one or more groups of attributes towhich said plurality of objects belong respectively; setting meshcreating specifications on an object attribute-by-attribute basisaccording to the one or more groups of attributes; and conducting meshcreations according to the set object attribute mesh creatingspecifications.
 9. The medium as claimed in claim 8, wherein saidattributes are grouped according to a categorization of the attributesand an attribute in each group of attributes is discriminated accordingto attribute discriminative information which designates discriminationswithin said attribute.
 10. The medium as claimed in claim 9, whereinsaid attribute category includes one or more of class, material, heatingelement or object name.
 11. The medium as claimed in claim 8, whereinsaid set mesh creating specifications for an attribute in a group ofattributes includes a number of division for an object belonging to theattribute in the group of attributes.
 12. The medium as claimed in claim8, wherein said mesh creating specifications for an attribute in a groupof attributes includes removal enable/disable information of an objectbelonging to the attribute in the group of attributes.
 13. The medium asclaimed in claim 8, wherein the mesh creation process further sets amesh creating specification for said plurality of objects in totalregardless of said groups of attributes to which said plurality ofobjects belong.
 14. An apparatus, comprising: a controller groupingattributes to which a plurality of objects belong; preparing a userinterface setting one or more mesh creating specifications on anattribute-by-attribute basis for an object, according to the grouping ofthe attributes; and generating one or more meshes of the plurality ofobjects, according to the one or more mesh creating specifications forthe object.